Comparison of the Effect of Traditional and Industrial Drying Methods in Raisins Production On Heavy Metals Concentrations

The present study was conducted to compare the effects of traditional and industrial methods on heavy metals concentrations in raisins. The concentration of heavy metals (cadmium, lead, nickel, copper, arsenic, and zinc) were examined in various types of raisin samples include Sultana, Golden Raisins, Shade-dried and Sun-dried raisins from Malayer city of Iran. Results showed that the mean concentrations of lead, nickel, copper, arsenic, and zinc were 0.08, 4.72, 3.07, 0.17, and 2.25 & x202f;mg/kg, respectively. The concentrations of arsenic, copper, and nickel in all raisin samples were higher than the limits recommended by FAO/WHO while for zinc, and lead (80.77% of samples) was lower or in the range of the permitted values by WHO/FAO, EC, and ISIRI. Also the highest concentrations of heavy metals in raisins were observed in industrial drying methods (Sultana and Golden raisins). We identified a positive correlation between zinc and nickel in raisin samples (P & x202f;< 0.01), while there was no correlation between the other elements.